Newton's Second Law Review (UNIT 2 REVIEW)

In Unit 2, I learned about Newton's second law. This law talks about the relations with force, acceleration, and mass. Acceleration has a verse relationship with force, but an inversely relationship with mass. If force is increased then acceleration increases, if mass increases then acceleration decreases, and vice-versa for both. Many people get this confused with the actual definition of acceleration, a=change in velocity over time, these relations are just proofs for the second law.
 I also learned about free fall, free falling at an angle, free falling when thrown up, and skydiving fall (fall with air resistance). Let's start with Free Fall basics.

Free Falling

In Free Fall there is no resistance. What does that mean? Well, no air resistance means like you're in space, where if you moving/falling nothing (no air) is being pushed against you, this means you fall at a constant acceleration.

For the constant acceleration of free fall, we use a=9.8m/s^2. Most of the times, like in labs we used a=10m/s^2. So every second, you increase your speed by 10m/s (9.8).

Last bit to remember mostly about free fall is weight/mass does not matter. If you had no air and dropped a feather and a brick, they would hit the ground at the exact same time.

Free Falling @ an Angle

So, have you ever heard about a plane that needs to drop a package, or you jumping off a cliff. Well, where do you/the package land, how long are you/the package in the air for. We can calculate all of this using d=1/2gt^2 and d=vt.

To find the time, use the height (vertical) distance to see how long it would take you to get to the ground. Let's say you were on a 250m high cliff and wanted to figure out how long it will take you to hit the ground, if you ran off at a constant speed of 5m/s. d=1/2gt^2 is the equation we will use, so 250=1/210(t^2), 250/5=t^2, 50=t^2, t=7.07 seconds.

Now that you have seconds you can see how far you will go too. d=vt is the equation we use for horizontal distance. Plug it in (d=5(7.07)), you will go 35.35 meters. To find the actual velocity you are going at any second, use a triangle, and see how to do the other things like so:

Special triangles are the right triangles in which we use the 345, and a^2+b^2=c^2

Free Falling When Thrown Up

Now we have a ball thats thrown up. You can see how, since there is still no air resistance, the ball will decrease in acceleration up by 10m/s^2 and increase on its way back down. 

To find the height, use the d=1/2gt^2, to find the total height of its highest part. Once you find this, you can use the same equation to find how high the ball is after 3s, 5s, etc.. Just use the same equation and then subtract it from the total height.

Also to do with an angle thrown, here is another video made by my friends to explain it better: 

Falling (Sky-Diving)